Background:Oxidative stress is the result of an imbalance between the rates of free radical production and elimination via endogenous antioxidant mechanisms such as antioxidant enzymes, which include glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT). There are mainly two vinegar production methods. The first is the surface method which is also known as the traditional method. The second method is known as the industrial method or submerged method which involves the use of a submerged culture with supplemented aeration.Objective: The aim of this study is to determine the effects of grape and apple cider vinegar consumption against oxidative stress in rats fed a high cholesterol diet.Methods: Fifty-four male, adult Wistar albino rats were included in this study. Rats were fed for 7 weeks by oral gavage as given in the experimental procedure. Rats were sacrificed at the end of the experiment and blood samples were collected. Catalase (CAT) activity, malondialdehyde level (MDA), glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity were analyzed. Grape and apple vinegar fermentation products prepared using both the surface culture method and submerged methods were prepared. The total antioxidant activity of vinegar samples were measured by Oxygen Radical Absorbance Capacity (ORAC) and 2,2'-azinobis (3-ethlybenzthiazoline)-6-sulfonic acid (ABTS) methods. Results: Levels of CAT, GSH-Px, SOD in high cholesterol diet group (CHCNT) were significantly decreased while MDA levels were significantly increased in control rats fed with the high-cholesterol diet (CHCNT) when compared to the Control group (CNT) (P<0.05). Levels of MDA, which is the end-product of lipid peroxidation, were significantly decreased in the apple cider vinegar administered groups when compared to the CHCNT (P<0.05). GSH-Px levels were significantly increased in rat groups, which were fed with the vinegars produced by traditional surface methods (P=0.03, P=0.001 respectively) as compared to the CHCNT. SOD levels of rat groups which were fed with all the vinegars were significantly increased as compared to CHCNT group (p<0.05).
Conclusions:This study indicated that a high cholesterol diet increased lipid peroxidation and consumed the antioxidant enzymes. Although the impact of vinegars on antioxidant enzyme activity differs, the use of vinegar and especially vinegars produced by surface culture methods seem to have favorable effect in vivo.